As is conventional module racks are used for receiving so-called plug-in modules having electric circuits and components mounted on a printed circuit board. The circuit boards, as a rule in rather large numbers, are inserted standing vertically adjacent to one another into the module rack, with the assistance of snapped-in guide rails. To cover the front, each plug-in module has a front panel. The front panels of vertically mutually adjacent plug-in modules constitute a nearly continuous cover on the front of the module rack.
Such a configuration is described in, for example, French Patent FR 1 578 231.
European Patent No. 0 262 450 describes a multipurpose desktop chassis composed of two equal side parts and one upper and one lower part. In their inner parts, the side parts have T-grooves, arranged spaced uniformly apart from one another and extending continuously vertically. Moreover, corner pieces have T-grooves oriented toward one another. Into these, for example, a flat rear wall may be inserted. A comparable arrangement is also described in European Patent No. 0 338 339.
A module rack, according to the exemplary illustration in FIG. 1, has on its front 38 at least one upper and one lower crossrail 3, 4 and one left and one right vertical corner profile strip 5, 6. The crossrails 3, 4 and corner profile strips 5, 6 are joined to form a frame. As a rule, side wall plates 1, 2 are additionally applied to the corner profile strips 5, 6, for lateral coverage of inserted plug-in modules.
The crossrails 3, 4 have horizontal mounting grooves, as a rule facing outward toward the front 38 of the module rack. In the example in FIG. 1, such a mounting groove 29 is visible on the lower crossrail 4. Detention means, such as threaded rail strips, cage nuts and the like may be mounted in this groove. In these retention means, in turn, external fastening means, such as screws, may be retained. Components inserted in the module rack are fastenable to the front 38 via the fastening means. For example, plug-in modules inserted into the module rack are fastened to the module rack at their upper and lower edges via screws extending through their front panels into the horizontal mounting grooves of the upper and lower crossrails, using fastening means inserted into those grooves.
In practice, it is increasingly desirable to be able to mount further components, parts, covers and the like on the front of a module rack, as a function of a given application. This need gives rise to the problem that the horizontal mounting grooves in the upper and lower crossrails, extending across the entire breadth of a module rack, are covered by the ends of the front panels of inserted plug-in modules, and then are no longer accessible to receive further retention means.
An object of the present invention is to provide a module rack in which expanded fastening capabilities are available on the front of the module rack, particularly for external add-on parts.